Memory macro disableable input-output circuits and methods of operating the same

ABSTRACT

A memory macro includes a first input terminal, a first memory cell array, a second memory cell array, a first input output (IO) circuit, a second IO circuit, a first set of driver circuits, a second set of driver circuits and a logic circuit. The first set of driver circuits are coupled to the first memory cell array and the first IO circuit. The second set of driver circuits are coupled to the second memory cell array and the second IO circuit. The logic circuit has a first terminal coupled to the first input terminal and configured to receive a first signal. The logic circuit is coupled to the first set of driver circuits and the second set of driver circuits. The logic circuit is configured to generate at least a second signal responsive to the first signal causing a change in the operational mode of the memory macro.

BACKGROUND

The semiconductor integrated circuit (IC) industry has produced a widevariety of digital devices to address issues in a number of differentareas. Some of these digital devices, such as memory macros, areconfigured for the storage of data. As ICs have become smaller and morecomplex, operating voltages of these digital devices continues todecrease affecting IC performance.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1A is a block diagram of a memory macro, in accordance with someembodiments.

FIG. 1B is a table illustrating operational modes of the memory macro ofFIG. 1A, in accordance with some embodiments.

FIG. 2 is a circuit diagram of a first logic circuit usable in FIG. 1A,in accordance with some embodiments.

FIG. 3A is a block diagram of another memory macro, in accordance withsome embodiments.

FIG. 3B is a table illustrating operational modes of the memory macro ofFIG. 3A, in accordance with some embodiments.

FIG. 4 is a circuit diagram of a second logic circuit usable in FIG. 3A,in accordance with some embodiments.

FIG. 5 is a flowchart of a method of operating a memory macro, such asthe memory macro of FIG. 1A or FIG. 3A, in accordance with someembodiments.

DETAILED DESCRIPTION

The following disclosure provides different embodiments, or examples,for implementing features of the provided subject matter. Specificexamples of components and arrangements are described below to simplifythe present disclosure. These are, of course, merely examples and arenot limiting. For example, the formation of a first feature over or on asecond feature in the description that follows may include embodimentsin which the first and second features are formed in direct contact, andmay also include embodiments in which additional features may be formedbetween the first and second features, such that the first and secondfeatures may not be in direct contact. In addition, the presentdisclosure may repeat reference numerals and/or letters in the variousexamples. This repetition is for the purpose of simplicity and clarityand does not in itself dictate a relationship between the variousembodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

In accordance with some embodiments, a memory macro is configured tooperate in a first mode or a second mode. The memory macro is configuredto receive a first input signal that causes memory macro to be in afirst or a second operational mode. In some embodiments, the firstoperational mode of the memory macro corresponds to a fully-operationalmode that does not utilize an active power reduction scheme. In someembodiments, the second operational mode of the memory macro correspondsto a half-operational mode that uses an active power reduction scheme toreduce the operational power of the memory macro.

In accordance with some embodiments, a memory macro includes a firstinput terminal, a first memory cell array, a second memory cell array, afirst input output (IO) circuit, a second IO circuit, a first set ofdriver circuits, a second set of driver circuits and a logic circuit.The first IO circuit is coupled to the first memory cell array and thesecond IO circuit is coupled to the second memory cell array. The firstset of driver circuits is coupled to the first memory cell array and thefirst IO circuit. The second set of driver circuits is coupled to thesecond memory cell array and the second IO circuit. The logic circuithas a first terminal coupled to the first input terminal, and configuredto receive a first signal. The logic circuit is coupled to the first setof driver circuits and the second set of driver circuits. The firstsignal indicates an operational mode of the memory macro. The logiccircuit is configured to generate at least a second signal responsive tothe first signal and wherein the second signal causes a change in theoperational mode of the memory macro.

FIG. 1A is a block diagram of a memory macro 100, in accordance withsome embodiments. In the embodiment of FIG. 1A, memory macro 100 is astatic random access memory (SRAM) macro. SRAM is used for illustration,and other types of memories are within the scope of various embodiments.

Memory macro 100 is configured to receive a first input signal MS. Firstinput signal MS is logically low or logically high. First input signalMS causes memory macro 100 to be in a first or a second operationalmode. For example, a first value of the first input signal MScorresponds to the first operational mode of memory macro 100, and asecond value of first input signal MS corresponds to the secondoperational mode of memory macro 100. First input signal MS is generatedexternal of memory macro 100. Memory macro 100 is configured to generatea first signal ML and a second signal MR responsive to the first inputsignal MS causing a change in the operational mode of the memory macro100. First signal ML or second signal MR is logically low or logicallyhigh.

Memory macro 100 includes a first memory cell array 104, a second memorycell array 106, a first IO circuit 108 a, a second IO circuit 108 b, afirst driver circuit region 110, a second driver circuit region 112, acontrol circuit 120 and a register circuit 122.

Memory macro 100 is symmetrical. For example, with reference to firstdriver circuit region 110, second driver circuit region 112 and controlcircuit 120, circuit elements on the left side are similar to circuitelements on the right side of memory macro 100.

First memory cell array 104 is coupled to first driver circuit region110 and second driver circuit region 112. First memory cell array 104 isalso coupled to first IO circuit 108 a (not shown). First memory cellarray 104 is configured to store data. First memory cell array 104 iscomprised of a first memory segment 104 a and a second memory segment104 b. First memory segment 104 a and second memory segment 104 b eachinclude a plurality of memory cells configured to store data. The memorycells in first memory segment 104 a or second memory segment 104 b arearranged in rows and columns. First memory segment 104 a and secondmemory segment 104 b are configured to share first IO circuit 108 a.

Second memory cell array 106 is coupled to first driver circuit region110 and second driver circuit region 112. Second memory cell array 106is coupled to second IO circuit 108 b (not shown). Second memory cellarray 106 is configured to store data. Second memory cell array 106 iscomprised of a first memory segment 106 a and a second memory segment106 b. First memory segment 106 a and second memory segment 106 b eachinclude a plurality of memory cells configured to store data. The memorycells in first memory segment 106 a or second memory segment 106 b arearranged in rows and columns. First memory segment 106 a and secondmemory segment 106 b are configured to share second IO circuit 108 b.First memory segment 104 a and first memory segment 106 a are configuredto share second driver circuit region 112. Second memory segment 104 band second memory segment 106 b are configured to share first drivercircuit region 110.

First IO circuit 108 a is coupled to first memory segment 104 a andsecond memory segment 104 b by data lines (not shown). First IO circuit108 a is also coupled to control circuit 120 by a first global IO lineGIO1. First IO circuit 108 a is configured to read data from and writedata to the first memory cell array 104 by data lines (not shown). FirstIO circuit 108 a is configured to receive control signals from controlcircuit 120 by first global IO line GIO1. First IO circuit 108 aincludes multiplexers, sense amplifiers, input drivers or outputdrivers.

Second IO circuit 108 b is coupled to first memory segment 106 a andsecond memory segment 106 b by data lines (not shown). Second IO circuit108 b is also coupled to control circuit 120 by a second global IO lineGIO2. Second IO circuit 108 b is configured to read data from and writedata to the second memory cell array 106 by data lines (not shown).Second IO circuit 108 b is configured to receive control signals fromcontrol circuit 120 by second global IO line GIO2. Second IO circuit 108b includes multiplexers, sense amplifiers, input drivers or outputdrivers.

First driver circuit region 110 is coupled to second memory segment 104b, second memory segment 106 b, control circuit 120 and first logiccircuit 134. First driver circuit region 110 is between second memorysegment 104 b and second memory segment 106 b. First driver circuitregion 110 is configured to receive first signal ML, second signal MRand control signals (not shown). In some embodiments, the controlsignals (not shown) correspond to word line data. First driver circuitregion 110 is configured to output word line signals (not shown) on wordlines WL0, . . . , WLn (where n is an integer corresponding to thenumber of word lines). First driver circuit region 110 includes a firstset of word line drivers 110 a and a second set of word line drivers 110b.

First set of word line drivers 110 a is configured to receive firstsignal ML and control signals (not shown). First set of word linedrivers 110 a is configured to generate word line signals (not shown) onword lines WL0, . . . , WLn connected to the second memory segment 104 bbased on first signal ML and control signals (not shown). First set ofword line drivers 110 a is configured to be turned on or off based onfirst signal ML. First set of word line drivers 110 a includes one ormore word line driver circuits that have an inverted enable input. Insome embodiments, first set of word line drivers 110 a includes one ormore word line driver circuits that have a non-inverted enable input.

Second set of word line drivers 110 b is configured to receive secondsignal MR and control signals (not shown). Second set of word linedrivers 110 b is configured to generate word line signals (not shown) onword lines WL0, . . . , WLn connected to the second memory segment 106 bbased on second signal MR and control signals (not shown). Second set ofword line drivers 110 b is configured to be turned on or off based onsecond signal MR. Second set of word line drivers 110 b includes one ormore word line driver circuits that have an inverted enable input. Insome embodiments, second set of word line drivers 110 b includes one ormore word line driver circuits that have a non-inverted enable input.

Second driver circuit region 112 is coupled to first memory segment 104a, first memory segment 106 a, control circuit 120 and first logiccircuit 134. Second driver circuit region 112 is between first memorysegment 104 a and first memory segment 106 a. Second driver circuitregion 112 is configured to receive first signal ML, second signal MRand control signals (not shown). Second driver circuit region 112 isconfigured to output word line signals (not shown) on word lines (notshown). Second driver circuit region 112 includes a first set of wordline drivers 112 a and a second set of word line drivers 112 b. Firstdriver circuit region 110 and second driver circuit region 112 areconfigured to share control circuit 120.

First set of word line drivers 112 a is configured to receive firstsignal ML and control signals (not shown). First set of word linedrivers 112 a is configured to generate word line signals (not shown) onword lines (not shown) connected to the first memory segment 104 a basedon first signal ML and control signals (not shown). First set of wordline drivers 112 a is configured to be turned on or off based on firstsignal ML. First set of word line drivers 112 a includes one or moreword line driver circuits that have an inverted enable input. In someembodiments, first set of word line drivers 112 a includes a pluralityof word line driver circuits that have a non-inverted enable input. Whenfirst set of word line drivers 110 a and first set of word line drivers112 a are turned off based on first signal ML, data stored in firstmemory cell array 104 is retained.

Second set of word line drivers 112 b is configured to receive secondsignal MR and control signals (not shown). Second set of word linedrivers 112 b is configured to generate word line signals (not shown) onword lines (not shown) connected to the first memory segment 106 a basedon second signal MR and control signals (not shown). Second set of wordline drivers 112 b is configured to be turned on or off based on secondsignal MR. Second set of word line drivers 112 b includes one or moreword line driver circuits that have an inverted enable input. In someembodiments, second set of word line drivers 112 b includes a pluralityof word line driver circuits that have a non-inverted enable input. Whensecond set of word line drivers 110 b and second set of word linedrivers 112 b are turned off based on second signal MR, data stored insecond memory cell array 106 is retained.

Control circuit 120 is coupled to first IO circuit 108 a, second IOcircuit 108 b, first driver circuit region 110 and second driver circuitregion 112. Control circuit 120 is configured to control reading datafrom and writing data to the first memory cell array 104 and the secondmemory cell array 106. Control circuit 120 is configured to controlfirst IO circuit 108 a by first global IO line GIO1. Control circuit 120is configured to control second IO circuit 108 b by second global IOline GIO2. Control circuit 120 is between first driver circuit region110 and second driver circuit region 112. Control circuit 120 is betweenfirst IO circuit 108 a and second IO circuit 108 b. Control circuit 120includes a first set of control driver circuit 120 a, a second set ofcontrol driver circuits 120 b and control logic circuit 120 c.

First set of control driver circuits 120 a is coupled to first logiccircuit 134 by second terminal 136 a and to first IO circuit 108 a byfirst global IO line GIO1. First set of control driver circuits 120 a isconfigured to receive first signal ML and control signals (not shown).First set of control driver circuits 120 a is configured to generatecontrol signals (not shown) on first global IO line GIO1 based on firstsignal ML and control signals (not shown) received from control circuit120. First set of control driver circuits 120 a is configured to beturned on or off based upon the first signal ML. First set of controldriver circuits 120 a includes one or more control driver circuits thathave an inverted enable input. In some embodiments, first set of controldriver circuits 120 a includes one or more control driver circuits thathave a non-inverted enable input. When first set of control drivercircuits 120 a are turned off based on first signal ML, data stored infirst IO circuit 108 a is retained.

Second set of control driver circuits 120 b is coupled to first logiccircuit 134 by third terminal 136 b and to second IO circuit 108 b bysecond global IO line GIO2. Second set of control driver circuits 120 bis configured to receive second signal MR and control signals (notshown). Second set of control driver circuits 120 b is configured togenerate control signals (not shown) on second global IO line GIO2 basedon second signal MR and control signals (not shown) received fromcontrol circuit 120. Second set of control driver circuits 120 b isconfigured to be turned on or off based upon the second signal MR.Second set of control driver circuits 120 b includes one or more controldriver circuits that have an inverted enable input. In some embodiments,second set of control driver circuits 120 b includes one or more controldriver circuits that have a non-inverted enable input. When second setof control driver circuits 120 b are turned off based on second signalMR, data stored in second IO circuit 108 b is retained.

Control logic circuit 120 c is configured to generate control signals(not shown) utilized by control circuit 120 to control first IO circuit108 a and second IO circuit 108 b. Control logic circuit 120 c iscoupled to first set of control driver circuits 120 a and second set ofcontrol driver circuits 120 b. Control logic circuit 120 c is configuredto send control signals (not shown) to first set of control drivercircuits 120 a and second set of control driver circuits 120 b.

Register circuit 122 is coupled to first driver circuit region 110,second driver circuit region 112 and control circuit 120. Registercircuit 122 is configured to receive first input signal MS. Registercircuit 122 is configured to generate first signal ML and second signalMR responsive to the first input signal MS causing a change in anoperational mode of the memory macro 100. Register circuit 122 islocated along an edge of memory macro 100. In some embodiments, registercircuit 122 is located in other regions of memory macro 100.

Register circuit 122 includes a first terminal 130 and a first logiccircuit 134. In some embodiments, register circuit 122 also includesinput pins/terminals or output pins/terminals configured to send orreceive data to or from memory macro 100. In some embodiments, registercircuit 122 also includes flip-flops, latches or output registersconfigured to store data.

First terminal 130 is coupled to first logic circuit 134. First terminal130 is configured to receive first input signal MS. First terminal 130is configured to transfer first input signal MS to first logic circuit134. First terminal 130 is an input terminal or an output terminal. Insome embodiments, first terminal 130 is an input pin or an output pin.First terminal 130 is located along an edge 150 of memory macro 100. Insome embodiments, first terminal 130 is located in other regions ofmemory macro 100.

First logic circuit 134 is coupled to first terminal 130, first drivercircuit region 110, second driver circuit region 112 and control circuit120. First logic circuit 134 is configured to receive first input signalMS. First logic circuit 134 is configured to generate first signal MLand second signal MR responsive to the first input signal MS, and firstsignal ML and second signal MR cause a change in an operational mode ofthe memory macro 100. In some embodiments, a change in an operationalmode of the memory macro 100 includes a change in an operational mode ofthe first driver circuit region 110 or the second driver circuit region112. In some embodiments, a change in an operational mode of the memorymacro 100 includes a change in an operational mode of the first set ofword line drivers 110 a and the first set of word line drivers 112 a. Insome embodiments, a change in an operational mode of the memory macro100 includes a change in an operational mode of the second set of wordline drivers 110 b and the second set of word line drivers 112 b. Insome embodiments, a change in an operational mode of the memory macro100 includes a change in an operational mode of the first set of controldriver circuits 120 a or the second set of control driver circuits 120b. In some embodiments, a change in an operational mode of the memorymacro 100 includes a change in an operational mode of the first IOcircuit 108 a or the second IO circuit 108 b.

First logic circuit 134 includes a first terminal 132, a second terminal136 a and a third terminal 136 b. First terminal 132 is coupled to firstterminal 130, and is configured to receive first input signal MS. Secondterminal 136 a is coupled to first driver circuit region 110, seconddriver circuit region 112 and control circuit 120, and is configured tooutput first signal ML. Third terminal 136 b is coupled to first drivercircuit region 110, second driver circuit region 112 and control circuit120, and is configured to output second signal MR.

Memory macro 100 is configured to operate in a first mode or a secondmode. In some embodiments, the first mode of memory macro 100corresponds to a fully-operational mode that does not employ an activepower reduction scheme. For example, in the first mode of memory macro100, each of the first set of control driver circuits 120 a, the firstset of word line drivers 112 a and the first set of word line drivers110 a are turned on by first signal ML, and each of the second set ofcontrol driver circuits 120 b, the second set of word line drivers 112 band the second set of word line drivers 110 b are turned on by secondsignal MR.

In some embodiments, the second mode of memory macro 100 corresponds toa half-operational mode that uses an active power reduction scheme. Insome embodiments, the second mode of memory macro 100 corresponds tomemory macro 100 utilizing 50% of the power when compared with the firstmode.

For example, in some embodiments, the second mode of memory macro 100corresponds to the driver circuits (e.g., first set of control drivercircuits 120 a, the first set of word line drivers 112 a and the firstset of word line drivers 110 a) on the left side of memory macro 100being turned on by first signal ML, and the driver circuits (e.g.,second set of control driver circuits 120 b, the second set of word linedrivers 112 b and the second set of word line drivers 110 b) on theright side of memory macro 100 being turned-off by second signal MR.

For example, in some other embodiments, the second mode of memory macro100 corresponds to the driver circuits (e.g., first set of controldriver circuits 120 a, the first set of word line drivers 112 a and thefirst set of word line drivers 110 a) on the left side of memory macro100 being turned-off by first signal ML, and the driver circuits (e.g.,second set of control driver circuits 120 b, the second set of word linedrivers 112 b and the second set of word line drivers 110 b) on theright side of memory macro 100 being turned on by second signal MR.

FIG. 1B is a table 100′ illustrating the operational modes of memorymacro 100 of FIG. 1A, in accordance with some embodiments.

Table 100′ comprises 2 rows and 2 columns of data. The first columncomprises a plurality of possible entries for first input signal MS. Thesecond column comprises a plurality of second entries for operationalmodes corresponding to a particular entry in the first column.

For example, in row 1, when first input signal MS is logically low,memory macro 100 is in the first operational mode. In some embodiments,the first operational mode of memory macro 100 corresponds to a normalor fully-operational mode that does not employ an active power reductionscheme.

For example, in row 2, when first input signal MS is logically high,memory macro 100 is in the second operational mode. In some embodiments,the second operational mode of memory macro 100 corresponds to ahalf-operational mode that uses an active power reduction scheme toreduce the operational power of memory macro 100 by 50% of the powerwhen compared with the first operational mode. In some embodiments, thehalf-operational mode corresponds to a left portion of memory macro 100being turned off and a right portion of memory macro 100 being turnedon. In some embodiments, the half-operational mode corresponds to theright portion of memory macro 100 being turned off and the left portionof memory macro 100 being turned on.

Table 100′ is used for illustration. Other values for first input signalMS and the corresponding operational modes are within the contemplatedscope of the present disclosure. In some embodiments, when first inputsignal MS is logically high, memory macro 100 is in the firstoperational mode. In some embodiments, when first input signal MS islogically low, memory macro 100 is in the second operational mode.

FIG. 2 is a circuit diagram of a first logic circuit 200 usable as thefirst logic circuit 134 of FIG. 1A or FIG. 3A, in accordance with someembodiments.

First logic circuit 200 comprises a first NAND gate 202 coupled to afirst inverter 204 and a second NAND gate 206 coupled to a secondinverter 208.

First logic circuit 200 is configured to receive first input signal MS,a first memory signal LSEL and a second memory signal RSEL. First logiccircuit 200 is configured to generate first signal ML and second signalMR based on first input signal MS, a first memory signal LSEL and asecond memory signal RSEL.

First NAND gate 202 has a first terminal 202 a configured to receive thefirst input signal MS. First terminal 202 a of first NAND gate 202 is anembodiment of first terminal 132 of first logic circuit (FIG. 1A). FirstNAND gate 202 has a second terminal 202 b configured to receive thefirst memory signal LSEL. First memory signal LSEL is logically low orlogically high. In some embodiments, first memory signal LSEL is aninternal memory signal of memory macro 100. First NAND gate 202 has athird terminal 202 c coupled to an input terminal 204 a of firstinverter 204, and configured to generate a first signal MLB based onfirst input signal MS and first memory signal LSEL.

First inverter 204 has a first terminal 204 a configured to receivefirst signal MLB. First inverter 204 has a second terminal 204 bconfigured to output first signal ML. First signal ML is an invertedversion of first signal MLB. Second terminal 204 b of first inverter 204is an embodiment of second terminal 136 a of first logic circuit (FIG.1A).

Second NAND gate 206 has a first terminal 206 a configured to receivethe first input signal MS. First terminal 206 a of second NAND gate 206is an embodiment of first terminal 132 of first logic circuit (FIG. 1A).Second NAND gate 206 has a second terminal 206 b configured to receivethe second memory signal RSEL. Second memory signal RSEL is logicallylow or logically high. In some embodiments, second memory signal RSEL isan internal memory signal of memory macro 100. Second NAND gate 206 hasa third terminal 206 c coupled to an input terminal 208 a of secondinverter 208, and configured to generate a second signal MRB based onfirst input signal MS and second memory signal RSEL.

Second inverter 208 has a first terminal 208 a configured to receivesecond signal MRB. Second inverter 208 has a second terminal 208 bconfigured to output second signal MR. Second signal MR is an invertedversion of second signal MRB. Second terminal 208 b of second inverter208 is an embodiment of third terminal 136 b of first logic circuit(FIG. 1A).

FIG. 3A is a block diagram of another memory macro 300, in accordancewith some embodiments. Memory macro 300 is an embodiment of memory macro100 (FIG. 1A). Components that are the same or similar to those in FIG.1A are given the same reference numbers, and detailed descriptionthereof is thus omitted.

Memory macro 300 is configured to operate in a first mode, a second modeor a third mode. In some embodiments, the first mode of memory macro 300corresponds to a fully-operational mode that does not utilize an activepower reduction scheme. In some embodiments, the second mode of memorymacro 300 corresponds to a half-operational mode that uses an activepower reduction scheme to reduce the operational power of memory macro300. In some embodiments, the third mode of memory macro 300 correspondsto a quarter-operational mode that uses an active power reduction schemeto reduce the operational power of memory macro 300.

Memory macro 300 is configured to receive first input signal MS and asecond input signal QIO. Second input signal QIO is logically low orlogically high. For memory macro 300, first input signal MS and secondinput signal QIO indicate the first, second or third operational mode ofmemory macro 300. Second input signal QIO is generated outside of memorymacro 300. Memory macro 300 is configured to generate a first outputsignal S1 and a second output signal S2 responsive to at least thesecond input signal QIO. In some embodiments, when the second orhalf-power operational mode is selected by first input signal MS, secondinput signal QIO causes a change in the operational mode of memory macro300. First output signal S1 or second output signal S2 is logically lowor logically high. In comparison with FIG. 1A, memory macro 300 alsoincludes a second terminal 320, a second logic circuit 330 and a set oftransistors 340.

In comparison with FIG. 1A, register circuit 122 of memory macro 300includes second terminal 320. In comparison with FIG. 1A, controlcircuit 120 of memory macro 300 includes second logic circuit 330. Incomparison with FIG. 1A, first IO circuit 108 a of memory macro 300includes set of transistors 340.

Second terminal 320 is coupled to second logic circuit 330. Secondterminal 320 is configured to receive second input signal QIO. Secondterminal 320 is configured to output second input signal QIO to secondlogic circuit 330. Second terminal 320 is an input terminal or an outputterminal. In some embodiments, second terminal 320 is an input pin or anoutput pin. Second terminal 320 is located along edge 150 of memorymacro 300. In some embodiments, second terminal 320 is located in otherregions of memory macro 300.

Second logic circuit 330 is coupled to first logic circuit 134, secondinput terminal 320 and first IO circuit 108 a. Second logic circuit 330is configured to receive second input signal QIO and first signal ML.Second logic circuit 330 is configured to generate first output signalS1 and second output signal S2 responsive to first signal ML and secondinput signal QIO causing a change in an operational mode of the memorymacro 300. In some embodiments, the change in the operational mode ofmemory macro 300 comprises turning off the second IO circuit 108 b andturning off 50% of the first IO circuit 108 a. In these embodiments,data in the first IO circuit 108 a and the second IO circuit 108 b isretained. In some embodiments, when the second or half-power operationalmode is selected by first input signal MS, second input signal QIOcauses a change in the operational mode of the first IO circuit 108 a.

Second logic circuit 330 is configured to turn off or on first IOcircuit 108 a. Second logic circuit 330 is configured to turn off or onthe first set of transistors 340 a based on first output signal S1.Second logic circuit 330 is configured to turn off or on the second setof transistors 340 b based on second output signal S2.

Second logic circuit 330 has a first input terminal 330 a, a secondinput terminal 330 b, a first output terminal 330 c, and a second outputterminal 330 d. The first input terminal 330 a of second logic circuit330 is coupled to the second terminal 320. The first input terminal 330a of the second logic circuit 330 is configured to receive a secondinput signal QIO. The second input terminal 330 b of the second logiccircuit 330 is coupled to second terminal 136 a of first logic circuit134. The second input terminal 330 b of the second logic circuit 330 isconfigured to receive first signal ML. The first output terminal 330 cof second logic circuit 330 is coupled to the first set of transistors340 a. The first output terminal 330 c of the second logic circuit 330is configured to output first output signal S1. The second outputterminal 330 d of the second logic circuit 330 is coupled to second setof transistors 340 b. The second output terminal 330 d of the secondlogic circuit 330 is configured to output second output signal S2.

Set of transistors 340 are configured to receive first output signal S1and second output signal S2. Set of transistors 340 are configured to beturned off or on based on first output signal S1 and second outputsignal S2. Set of transistors 340 are coupled to second memory segment104 b and second logic circuit 330. Set of transistors 340 is comprisedof a first set of transistors 340 a and a second set of transistors 340b.

The first set of transistors 340 a is coupled to second memory segment104 b and second logic circuit 330. The first set of transistors 340 ais configured to receive the first output signal S1 causing the firstset of transistors 340 a to be turned off or on. The first set oftransistors 340 a includes one or more P-type Metal Oxide Semiconductor(PMOS) transistors. In some embodiments, the first set of transistors340 a includes one or more N-type Metal Oxide Semiconductor (NMOS)transistors.

The second set of transistors 340 b is coupled to the second memorysegment 104 b and the second logic circuit 330. The second set oftransistors 340 b is configured to receive the second output signal S2causing the second set of transistors 340 b to be turned off or on. Thesecond set of transistors 340 b includes one or more PMOS transistors.In some embodiments, the second set of transistors 340 b includes one ormore NMOS transistors.

In some embodiments, when the second or half-power operational mode isselected by first input signal MS and second input signal QIO, the firstset of transistors 340 a and the second set of transistors 340 b areturned on. In some embodiments, when the third or quarter-poweroperational mode is selected by first input signal MS and second inputsignal QIO, one of the first set of transistors 340 a or the second setof transistors 340 b is turned on, and the other of the first set oftransistors 340 a or the second set of transistors 340 b is turned off.

FIG. 3A is used for illustration. Other arrangements for second logiccircuit 330, second IO circuit 108 b, or set of transistors 340 arewithin the contemplated scope of the present disclosure. For example, insome embodiments, second logic circuit 330 or set of transistors 340 arelocated on the right side of memory macro 300. In this example, thesecond input terminal 330 b of the second logic circuit 330 is coupledto third terminal 136 b of first logic circuit 134. In this example, thesecond input terminal 330 b of the second logic circuit 330 isconfigured to receive second signal MR. In this example, set oftransistors 340 is located in the second IO circuit 108 b. In thisexample, the first set of transistors 340 a and the second set oftransistors 340 b are coupled to second memory segment 106 b. In thisexample, when the second or half-power operational mode is selected byfirst input signal MS, second input signal QIO causes a change in theoperational mode of the second IO circuit 108 b. For example, anadditional set of transistors (similar to the set of transistors 340) islocated above second memory segment 104 b. In this example, theadditional set of transistors (similar to the set of transistors 340) isutilized to lower the power level provided to the second memory segment104 b without impacting the retention of data stored in memory cells ofthe second memory segment 104 b.

Memory macro 100 (FIG. 1A) or memory macro 300 (FIG. 3A) occupies lessarea than other memory macro circuits (not utilizing the features ofmemory macro 100 or memory macro 300) that also have active powerreduction techniques. The area of memory macro 100 (FIG. 1A) or memorymacro 300 (FIG. 3A) is increased by 1% to 2% when compared with othermemory macro circuits (not utilizing the features of memory macro 100 ormemory macro 300), but the circuit modifications/design changes ofmemory macro 100 or memory macro 300 are reduced when compared withother memory macro circuits having active power reduction techniques(e.g., floating bit lines which require a number of circuitmodifications to the memory macro). Furthermore, the active powerreduction techniques of memory macro 100 (FIG. 1A) or memory macro 300(FIG. 3A) does not affect normal memory performance unlike other memorymacro circuits (not utilizing the features of memory macro 100 or memorymacro 300).

Memory macro 100 (FIG. 1A) or memory macro 300 (FIG. 3A) has lesscircuit modifications than other memory macro circuits (not utilizingthe features of memory macro 100 or memory macro 300) that also haveactive power reduction techniques.

FIG. 3B is a table 300′ illustrating the operational modes of memorymacro 300 of FIG. 3A, in accordance with some embodiments.

Table 300′ comprises 3 rows and 4 columns of data. The first columncomprises a plurality of entries for first input signal MS. The secondcolumn comprises a plurality of entries for second input signal QIO. Thethird column comprises a plurality of second entries for operationalmodes. The fourth column comprises a plurality of second entries for IOpercentage (e.g., IO %).

For example, in row 1, when first input signal MS is logically low,memory macro 300 is in the first operational mode regardless of thelogical state of second input signal QIO. In some embodiments, the firstoperational mode of memory macro 300 corresponds to a normal orfully-operational mode that does not employ an active power reductionscheme and therefore the IO percentage for row 1 is 100%. In thisembodiment, the first IO circuit 108 a and the second IO circuit 108 bare both operational.

For example, in row 2, when first input signal MS is logically high andsecond input signal QIO is logically low, memory macro 300 is in thesecond operational mode. In some embodiments, the second operationalmode of memory macro 300 corresponds to a half-operational mode thatuses an active power reduction scheme to reduce the operational power ofthe IO circuits (e.g., first IO circuit 108 a or second IO circuit 108b) of memory macro 300 by 50% of the power when compared with the firstoperational mode. In this embodiment, the IO percentage for row 2 is50%. In this embodiment, one of the first IO circuit 108 a or the secondIO circuit 108 b is operational (e.g., turned on), and the other of thefirst IO circuit 108 a or the second IO circuit 108 b is not operational(e.g., turned-off).

For example, in row 3, when first input signal MS is logically high andsecond input signal QIO is logically high, memory macro 300 is in thethird operational mode. In some embodiments, the third operational modeof memory macro 300 corresponds to a quarter-operational mode that usesan active power reduction scheme to reduce the operational power of theIO circuits (e.g., first IO circuit 108 a or second IO circuit 108 b) ofmemory macro 300 by 75% of the power when compared with the firstoperational mode. In this embodiment, the IO percentage for row 3 is 25%indicating that the operational power of the IO circuits (e.g., first IOcircuit 108 a or second IO circuit 108 b) of memory macro 300 is 25% ofthe power when compared with the first operational mode. For example, inthis embodiment, one of the first IO circuit 108 a or the second IOcircuit 108 b is partially operational, and the other of the first IOcircuit 108 a or the second IO circuit 108 b is not operational (e.g.,turned-off). In this embodiment, the partially operational IO circuithas a first portion of first IO circuit 108 a or second IO circuit 108 bturned on, and a second portion of corresponding first IO circuit 108 aor corresponding second IO circuit 108 b turned-off. For example, if thefirst IO circuit 108 a is partly operational, then the second IO circuit108 b is not operational (e.g., turned off). In this example, firstcircuit 108 a has a first portion that is operational (e.g., turned on),and a second portion that is not operational (turned off).

Table 300′ is used for illustration. Other values for first input signalMS, second input signal QIO or the corresponding operational modes arewithin the contemplated scope of the present disclosure. For example,other values for first input signal MS and the corresponding operationalmodes are within the contemplated scope of the present disclosure. Insome embodiments, when first input signal MS is logically high, memorymacro 100 is in the first operational mode regardless of the logicalstate of second input signal QIO. In some embodiments, when first inputsignal MS is logically low, memory macro 100 is in the second or thirdoperational mode. For example, other values for second input signal QIOand the corresponding operational modes are within the contemplatedscope of the present disclosure.

FIG. 4 is a circuit diagram of a second logic circuit 400 usable as thesecond logic circuit 330 of FIG. 3A, in accordance with someembodiments.

Second logic circuit 400 comprises a first NAND gate 402 coupled to afirst path 404 and a second path 406. Second logic circuit 400 isconfigured to receive first signal ML and second input signal QIO.Second logic circuit 400 is configured to generate first output signalS1 and second output signal S2 based on first signal ML and second inputsignal QIO.

First NAND gate 402 has a first terminal 402 a configured to receive thefirst signal ML. First NAND gate 402 has a second terminal 402 bconfigured to receive the second input signal QIO. First NAND gate 402has a third terminal 402 c coupled to first path 404 and second path406, and configured to generate a first intermediate signal IS1 based onfirst signal ML and second input signal QIO.

First path 404 is configured to receive first intermediate signal IS1,and to output second output signal S2 based on first intermediate signalIS1. First path 404 includes a first plurality of inverters 404configured to generate second output signal S2 based on firstintermediate signal IS1. First plurality of inverters 404 includes Ninverters coupled in series, where N is an odd integer equal to orgreater than 1.

Second path 406 is configured to receive first intermediate signal IS1and second input signal QIO, and to generate first output signal S1based on first intermediate signal IS1 and second input signal QIO.Second path 406 includes a first portion 408 a, a second portion 408 band a delay circuit 408 c.

First portion 408 a includes a first inverter 420 coupled to a firsttransmission gate 422.

First inverter 420 has a first terminal 420 a coupled to the thirdterminal 402 c of NAND gate 402, and configured to receive firstintermediate signal IS1. First inverter 420 has a second terminal 420 bconfigured to generate inverted first intermediate signal IS1B.

First transmission gate 422 has an input terminal 422 a coupled to thesecond terminal 420 b of first inverter 420, and configured to receiveinverted first intermediate signal IS1B. First transmission gate 422 hasa control terminal 422 b configured to receive inverted second inputsignal QIOB. First transmission gate 422 has an inverted controlterminal 422 c configured to receive second input signal QIO. Firsttransmission gate 422 has an output terminal 422 d coupled to areference node Ref_A, and configured to output a signal S1′ based onsecond input signal QIO and inverted second input signal QIOB. In someembodiments, signal S1′ is equal to inverted first intermediate signalIS1B when the second transmission gate 432 is configured to passinverted first intermediate signal IS1B (e.g., the transistors in firsttransmission gate 422 are turned on).

Second portion 408 b includes a second inverter 430 coupled to a secondtransmission gate 432.

Second inverter 430 has a first terminal 430 a configured to receivesecond input signal QIO. Second inverter 430 has a second terminal 430 bconfigured to generate inverted second input signal QIOB.

Second transmission gate 432 has an input terminal 432 a coupled to thesecond terminal 430 b of second inverter 430, and configured to receiveinverted second input signal QIOB. Second transmission gate 432 has acontrol terminal 432 b configured to receive second input signal QIO.Second transmission gate 432 has an inverted control terminal 432 cconfigured to receive inverted second input signal QIOB. Secondtransmission gate 432 has an output terminal 432 d coupled to referencenode Ref_A, and configured to output a signal S1′ based on second inputsignal QIO and inverted second input signal QIOB. In some embodiments,signal S1′ is equal to inverted second input signal QIOB when the secondtransmission gate 432 is configured to pass inverted second input signalQIOB (e.g., the transistors in second transmission gate 432 are turnedon).

Delay circuit 408 c is coupled to first portion 408 a and second portion408 b by reference node Ref_A. Delay circuit 408 c is configured toreceive signal S1′, and to output first output signal S1. First outputsignal S1 is a delayed version of signal S1′. First output signal S1 isequal to inverted second input signal QIOB or inverted firstintermediate signal IS1B. Delay circuit 408 c includes M inverterscoupled in series, where M is an even integer equal to or greater than2. In some embodiments, delay circuit 424 is optional.

FIG. 5 is a flowchart of a method of operating a memory macro, such asthe memory macro depicted in FIG. 1A or FIG. 3A, in accordance with someembodiments. It is understood that additional operations may beperformed before, during, and/or after the method 500 depicted in FIG.5, and that some other processes may only be briefly described herein.

Method 500 begins with operation 502, where a first signal (e.g., firstinput signal MS (FIG. 1A)) is received by a first input terminal (e.g.,first terminal 130) of the memory macro (e.g., memory macro 100 ormemory macro 300). In some embodiments, first signal (e.g., first inputsignal MS) indicates a first operational mode of the memory macro. Insome embodiments, the first operational mode of the memory macrocorresponds to a first set of driver circuits (e.g., first set of wordline drivers 110 a, first set of word line drivers 112 a or controldriver circuits 120 a) and a second set of driver circuits (e.g., secondset of word line drivers 110 b, second set of word line drivers 112 b orcontrol driver circuits 120 b) being active. In some embodiments, thefirst operational mode of the memory macro corresponds to either thefirst set of driver circuits (e.g., first set of word line drivers 110a, first set of word line drivers 112 a or control driver circuits 120a) or the second set of driver circuits (e.g., second set of word linedrivers 110 b, second set of word line drivers 112 b or control drivercircuits 120 b) being active. In some embodiments, the first operationalmode of the memory macro corresponds to the first set of driver circuits(e.g., first set of word line drivers 110 a, first set of word linedrivers 112 a or control driver circuits 120 a) being turned on, and thesecond set of driver circuits (e.g., second set of word line drivers 110b, second set of word line drivers 112 b or control driver circuits 120b) being turned off.

Method 500 continues with operation 504, where a second signal (e.g.,first signal ML or second signal MR (FIG. 1A)) and a third signal (e.g.,second signal MR or first signal ML) are generated by a first logiccircuit (e.g., first logic circuit 134 or first logic circuit 200) basedon the first signal (e.g., first input signal MS) causing a change inthe first operational mode of the memory macro (e.g., memory macro 100or memory macro 300).

In some embodiments, the first logic circuit (e.g., first logic circuit134 or first logic circuit 200) is coupled to a first set of drivercircuits (e.g., first set of word line drivers 110 a, first set of wordline drivers 112 a or control driver circuits 120 a) and a second set ofdriver circuits (e.g., second set of word line drivers 110 b, second setof word line drivers 112 b or control driver circuits 120 b). In someembodiments, the first set of driver circuits (e.g., first set of wordline drivers 110 a, first set of word line drivers 112 a or controldriver circuits 120 a) are coupled to a first memory cell array (e.g.,first memory cell array 104) and a first IO circuit (e.g., first IOcircuit 108 a), and the second set of driver circuits (e.g., second setof word line drivers 110 b, second set of word line drivers 112 b orcontrol driver circuits 120 b) are coupled to a second memory cell array(e.g., second memory cell array 106) and a second IO circuit (e.g.,second IO circuit 108 b).

In some embodiments, generating the second signal (e.g., first signal MLor second signal MR) and the third signal (e.g., second signal MR orfirst signal ML) based on the first signal (e.g., first input signal MS)of operation 504 includes generating a fourth signal (e.g., first signalMLB (FIG. 2)) by a first NAND gate (e.g., first NAND gate 202) based onthe first signal (e.g., first input signal MS) and a first memory signal(e.g., first memory signal LSEL), generating an inverted fourth signal(e.g., first signal ML (FIG. 2)) by a first inverter (e.g., firstinverter 204) based on the fourth signal (e.g., first signal MLB),generating a fifth signal (e.g., second signal MRB (FIG. 2)) by a secondNAND gate (e.g., second NAND gate 206) based on the first signal (e.g.,first input signal MS) and a second memory signal (e.g., second memorysignal RSEL), and generating an inverted fifth signal (e.g., secondsignal MR (FIG. 2)) by a second inverter (e.g., second inverter 208)based on the fifth signal (e.g., second signal MRB).

In some embodiments, causing the change in the first operational mode ofthe memory macro (e.g., memory macro 100 or 300) of operation 504comprises turning off or on the first set of driver circuits ((e.g.,first set of word line drivers 110 a, first set of word line drivers 112a and control driver circuits 120 a (FIG. 1A)) based on the invertedfourth signal (e.g., first signal ML (FIG. 2)), or turning off or on thesecond set of driver circuits (e.g., second set of word line drivers 110b, second set of word line drivers 112 b or control driver circuits 120b) (FIG. 1A)) based on the inverted fifth signal (e.g., second signal MR(FIG. 2)).

Method 500 continues with operation 506, where a second input terminal(e.g., second input terminal 320 (FIG. 3A)) receives a fourth signal(e.g., second input signal QIO) indicating a second operational mode ofthe memory macro. In some embodiments, the second operational mode ofthe memory macro corresponds to 50% of the first IO circuit or thesecond IO circuit being inactive. In some embodiments, operations 506and 508 are optional. In some embodiments, the second operational modeof the memory macro corresponds to 50% of the first IO circuit beingactive and 100% of the second IO circuit being active, such that 75% ofthe IO circuits (e.g., first IO circuit and second IO circuit) areactive.

Method 500 continues with operation 508, where a second logic circuit(e.g., second logic circuit 330 or second logic circuit 400) generates afifth signal (e.g., first output signal S1 (FIG. 4)) and a sixth signal(e.g., second output signal S2) based on the second signal (e.g., firstsignal ML) and the fourth signal (e.g., second input signal QIO) causinga change in the second operational mode of the memory macro (e.g.,memory macro 100 or memory macro 300). In some embodiments, the secondlogic circuit (e.g., second logic circuit 330 or second logic circuit400) is coupled to the first IO circuit (e.g., first IO circuit 108 a(FIG. 3A)) and the first logic circuit (e.g., first logic circuit 134),and the first IO circuit (e.g., first IO circuit 108 a (FIG. 3A)) iscoupled to the first memory cell array (e.g., first memory cell array104).

In some embodiments, generating the fifth signal (e.g., first outputsignal S1 (FIG. 4)) and a sixth signal (e.g., second output signal S2)based on the second signal (e.g., first signal ML) and the fourth signal(e.g., second input signal QIO) of operation 508 includes generating aseventh signal (e.g., first intermediate signal IS1 (FIG. 4)) by a NANDgate (e.g., first NAND gate 402) based on the fourth signal (e.g.,second input signal QIO) and an intermediate signal (e.g., first signalML), outputting an inverted seventh signal (e.g., inverted firstintermediate signal IS1B) by a first path (e.g., first path 404) basedon the seventh signal (e.g., first intermediate signal IS1), andoutputting an inverted fourth signal (e.g., inverted second input signalQIOB) or the inverted seventh signal (e.g., inverted first intermediatesignal IS1B) by a second path (e.g., second path 406). In someembodiments, for operation 508, the intermediate signal (e.g., firstsignal ML) is based on at least the first signal (e.g., first inputsignal MS).

In some embodiments, for operation 508, the first path (e.g., first path404) includes a plurality of inverters (e.g., plurality of inverters410), and the second path (e.g., second path 406) includes a firstinverter (e.g., first inverter 420 or second inverter 430) and a switch(e.g., first transmission gate 422 or second transmission gate 432).

In some embodiments, causing the change in the second operational modeof the memory macro (e.g., memory macro 100 or 300) of operation 508comprises turning off or on a first portion (e.g., first set of IOcircuits 340 a (FIG. 3A)) of the first IO circuit (e.g., first IOcircuit 108 a) based on the inverted seventh signal (e.g., invertedfirst intermediate signal IS1B or second output signal S2), and turningoff or on a second portion (e.g., second set of IO circuits 340 b (FIG.3A)) of the first IO circuit (e.g., first IO circuit 108 a) based on theinverted fourth signal (e.g., inverted second input signal QIOB or firstoutput signal S1) or the inverted seventh signal (e.g., inverted firstintermediate signal IS1B or first output signal S1).

In some embodiments, for operation 508, the first portion (e.g., firstset of IO circuits 340 a (FIG. 3A)) of the first IO circuit (e.g., firstIO circuit 108 a) is 50% of the first IO circuit (e.g., first IO circuit108 a) and the second portion (e.g., second set of IO circuits 340 b(FIG. 3A)) of the first IO circuit (e.g., first IO circuit 108 a) is 50%of the first IO circuit (e.g., first IO circuit 108 a).

One aspect of this description relates to a memory macro. The memorymacro includes a first input terminal, a first memory cell array, asecond memory cell array, a first input output (IO) circuit, a second IOcircuit, a first set of driver circuits, a second set of driver circuitsand a logic circuit. The first IO circuit is coupled to the first memorycell array and the second IO circuit is coupled to the second memorycell array. The first set of driver circuits is coupled to the firstmemory cell array and the first IO circuit. The second set of drivercircuits is coupled to the second memory cell array and the second IOcircuit. The logic circuit has a first terminal coupled to the firstinput terminal, and configured to receive a first signal. The logiccircuit is coupled to the first set of driver circuits and the secondset of driver circuits. The first signal indicates an operational modeof the memory macro. The logic circuit is configured to generate atleast a second signal responsive to the first signal causing a change inthe operational mode of the memory macro.

Another aspect of this description relates to a memory macro. The memorymacro includes a first input terminal, a first memory cell array, asecond memory cell array, a first input output (IO) circuit, a second IOcircuit and a first logic circuit. The first IO circuit is coupled tothe first memory cell array. The second IO circuit is coupled to thesecond memory cell array. The first logic circuit has a first terminaland a second terminal. The first terminal of the first logic circuit iscoupled to the first input terminal, and configured to receive a firstsignal. The second terminal of the first logic circuit is configured toreceive a second signal. The first signal indicates an operational modeof the memory macro. The first logic circuit is configured to generate athird signal responsive to the first signal and the second signalcausing a change in the operational mode of the memory macro.

Still another aspect of this description relates to a method ofoperating a memory macro. The method includes receiving, by a firstinput terminal of the memory macro, a first signal indicating a firstoperational mode of the memory macro. The method further includesgenerating, by a first logic circuit, a second signal and a third signalbased on the first signal causing a change in the first operational modeof the memory macro. The first logic circuit is coupled to a first setof driver circuits and a second set of driver circuits. The first set ofdriver circuits is coupled to a first memory cell array and a firstinput output (IO) circuit. The second set of driver circuits is coupledto a second memory cell array and a second IO circuit.

A number of embodiments have been described. It will nevertheless beunderstood that various modifications may be made without departing fromthe spirit and scope of the disclosure. For example, various transistorsbeing shown as a particular dopant type (e.g., N-type or P-type MetalOxide Semiconductor (NMOS or PMOS)) are for illustration purposes.Embodiments of the disclosure are not limited to a particular type.Selecting different dopant types for a particular transistor is withinthe scope of various embodiments. The low or high logical value ofvarious signals used in the above description is also for illustration.Various embodiments are not limited to a particular logical value when asignal is activated and/or deactivated. Selecting different logicalvalues is within the scope of various embodiments. In variousembodiments, a transistor functions as a switch. A switching circuitused in place of a transistor is within the scope of variousembodiments. In various embodiments, a source of a transistor can beconfigured as a drain, and a drain can be configured as a source. Assuch, the term source and drain are used interchangeably. Varioussignals are generated by corresponding circuits, but, for simplicity,the circuits are not shown.

Various figures show capacitive circuits using discrete capacitors forillustration. Equivalent circuitry may be used. For example, acapacitive device, circuitry or network (e.g., a combination ofcapacitors, capacitive elements, devices, circuitry, etc.) can be usedin place of the discrete capacitor. The above illustrations includeexemplary steps, but the steps are not necessarily performed in theorder shown. Steps may be added, replaced, changed order, and/oreliminated as appropriate, in accordance with the spirit and scope ofdisclosed embodiments.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A memory macro comprising: a first inputterminal; a first memory cell array; a second memory cell array; a firstinput output (IO) circuit coupled to the first memory cell array; asecond IO circuit coupled to the second memory cell array; a first setof driver circuits and a second set of driver circuits, the first set ofdriver circuits being coupled to the first memory cell array and thefirst IO circuit, and the second set of driver circuits being coupled tothe second memory cell array and the second IO circuit; and a logiccircuit having a first terminal coupled to the first input terminal andbeing configured to receive a first signal, the logic circuit beingcoupled to the first set of driver circuits and the second set of drivercircuits, the first signal indicating an operational mode of the memorymacro, and the logic circuit being configured to generate at least asecond signal responsive to the first signal, and cause a change in theoperational mode of the memory macro, the logic circuit comprising: aNAND gate configured to receive at least the first signal, and togenerate the second signal; and a first path having a plurality ofinverters configured to generate an inverted second signal based on thesecond signal, the first path being coupled to the NAND gate, and thefirst path being configured to output the inverted second signal.
 2. Thememory macro of claim 1, wherein the change in the operational mode ofthe memory macro comprises: turning off the first set of driver circuitsor the second set of driver circuits; or turning on the first set ofdriver circuits or the second set of driver circuits.
 3. The memorymacro of claim 2, wherein data stored in the first memory cell array orthe second memory cell array is retained; or data in the first IOcircuit or the second IO circuit is retained.
 4. The memory macro ofclaim 1, wherein a portion of the first set of driver circuits iscoupled to a first global IO line of the first IO circuit, and a portionof the second set of driver circuits is coupled to a second global IOline of the second IO circuit.
 5. The memory macro of claim 1, whereinthe first set of driver circuits include a first set of word line drivercircuits coupled to at least a first word line of the first memory cellarray, and the second set of driver circuits include a second set ofword line driver circuits coupled to at least a second word line of thesecond memory cell array.
 6. The memory macro of claim 1, wherein thefirst input terminal or the logic circuit is located along an edge ofthe memory macro.
 7. The memory macro of claim 1, wherein the logiccircuit further comprises: a second path coupled to the NAND gate, thesecond path being configured to output the inverted second signal or aninverted first signal.
 8. A memory macro comprising: a first inputterminal; a first memory cell array; a second memory cell array; a firstinput output (IO) circuit coupled to the first memory cell array; asecond IO circuit coupled to the second memory cell array; and a firstlogic circuit having a first terminal and a second terminal, the firstterminal of the first logic circuit being coupled to the first inputterminal and being configured to receive a first signal, the secondterminal of the first logic circuit being configured to receive a secondsignal, the first signal indicating an operational mode of the memorymacro, and the first logic circuit being configured to generate a thirdsignal responsive to the first signal and the second signal, and cause achange in the operational mode of the memory macro, the first logiccircuit comprising: a first NAND gate having a first terminal, a secondterminal and a third terminal, the first terminal of the first NAND gatebeing configured to receive the first signal, and the third terminal ofthe first NAND gate being configured to generate a fourth signal; and afirst path having a plurality of inverters configured to generate aninverted fourth signal, the first path being coupled to the thirdterminal of the first NAND gate, and the first path being configured tooutput the inverted fourth signal.
 9. The memory macro of claim 8,wherein the change in the operational mode of the memory macro comprisesturning off the second IO circuit.
 10. The memory macro of claim 9,wherein the change in the operational mode of the memory macro furthercomprises turning off 50% of the first IO circuit; and data in the firstIO circuit or the second IO circuit is retained.
 11. The memory macro ofclaim 8, wherein the second terminal of the first NAND gate isconfigured to receive the second signal, and the first logic circuitfurther comprises: a second path coupled to the third terminal of thefirst NAND gate, the second path being configured to output the invertedfourth signal or an inverted first signal, wherein the third signalincludes the inverted fourth signal or the inverted first signal. 12.The memory macro of claim 11, wherein the second path comprises: aninverter configured to generate the inverted fourth signal or theinverted first signal; and a switch coupled to an output terminal of theinverter, the switch being configured to output the inverted fourthsignal or the inverted first signal based on the first signal and theinverted first signal.
 13. The memory macro of claim 12, wherein thefirst IO circuit comprises: a first set of transistors coupled to thefirst memory cell array and the first logic circuit, the first set oftransistors being configured to receive the inverted fourth signalcausing the first set of transistors to be turned off or on; and asecond set of transistors coupled to the first memory cell array and thefirst logic circuit, the second set of transistors being configured toreceive the inverted first signal causing the second set of transistorsto be turned off or on, and the first logic circuit being configured toturn off or on the first set of transistors and the second set oftransistors.
 14. The memory macro of claim 8, further comprising: asecond input terminal; a first set of driver circuits and a second setof driver circuits, the first set of driver circuits being coupled tothe first memory cell array and the first IO circuit, and the second setof driver circuits being coupled to the second memory cell array and thesecond IO circuit; and a second logic circuit having a first terminalcoupled to the second input terminal, and being configured to receive afifth signal, the second logic circuit being coupled to the secondterminal of the first logic circuit, the first set of driver circuitsand the second set of driver circuits, the second logic circuit beingconfigured to generate at least the second signal responsive to thefifth signal causing a change in an operational mode of the first set ofdriver circuits or the second set of driver circuits.
 15. The memorymacro of claim 14, wherein the change in the operational mode of thefirst set of driver circuits or the second set of driver circuitscomprises: turning off the first set of driver circuits or the secondset of driver circuits; or turning on the first set of driver circuitsor the second set of driver circuits.
 16. The memory macro of claim 15,wherein data stored in the first memory cell array or the second memorycell array is retained.
 17. A method of operating a memory macro, themethod comprising: receiving, by a first input terminal of the memorymacro, a first signal indicating a first operational mode of the memorymacro; and generating, by a first logic circuit, a second signal and athird signal based on the first signal thereby causing a change in thefirst operational mode of the memory macro, the first logic circuitbeing coupled to a first set of driver circuits and a second set ofdriver circuits, the first set of driver circuits being coupled to afirst memory cell array and a first input output (IO) circuit, and thesecond set of driver circuits being coupled to a second memory cellarray and a second IO circuit, wherein generating the second signal andthe third signal based on the first signal comprises: generating, by afirst NAND gate, a first NAND output signal based on the first signaland a first memory signal; and generating, by a first inverter, aninverted first NAND output signal based on the first NAND output signal,the first inverter being coupled to the first NAND gate, the secondsignal being the inverted first NAND output signal.
 18. The method ofclaim 17, wherein generating the second signal and the third signalbased on the first signal further comprises: generating, by a secondNAND gate, a second NAND output signal based on the first signal and asecond memory signal; and generating, by a second inverter, an invertedsecond NAND output signal based on the second NAND output signal;causing the change in the first operational mode of the memory macrocomprises: turning off or on the first set of driver circuits based onthe inverted first NAND output signal, the first set of driver circuitsbeing coupled to the first memory cell array or the first input output(IO) circuit; or turning off or on the second set of driver circuitsbased on the inverted second NAND output signal, the second set ofdriver circuits being coupled to the second memory cell array or thesecond IO circuit.
 19. The method of claim 17, further comprising:receiving, by a second input terminal, a fourth signal indicating asecond operational mode of the memory macro; and generating, by a secondlogic circuit, a fifth signal and a sixth signal based on the secondsignal and the fourth signal and causing a change in the secondoperational mode of the memory macro, the second logic circuit beingcoupled to the first IO circuit and the first logic circuit, and thefirst IO circuit being coupled to the first memory cell array.
 20. Themethod of claim 19, wherein generating the fifth signal and the sixthsignal based on the second signal and the fourth signal comprises:generating, by a second NAND gate, a seventh signal based on the fourthsignal and an intermediate signal, the intermediate signal being basedon at least the first signal; outputting, by a first path, an invertedseventh signal based on the seventh signal, the first path comprising aplurality of inverters; and outputting, by a second path, an invertedfourth signal or the inverted seventh signal, the second path comprisinga first inverter and a switch; causing the change in the secondoperational mode of the memory macro comprises: turning off or on afirst portion of the first IO circuit based on the inverted seventhsignal, the first portion of the first IO circuit corresponding to 50%of the first IO circuit; and turning off or on a second portion of thefirst IO circuit based on the inverted fourth signal or the invertedseventh signal, the second portion of the first IO circuit correspondingto 50% of the first IO circuit.